1. Technical Field
The present invention relates to an electric connector, an electronic device, and an electrically-conductive touch method.
2. Related Art
Various electric connectors are used in the electronic device. Among others, it is necessary that the electric connector that gets into electrically-conductive touch with an electrode of a battery have a large displacement amount so as to be able to absorb not only a dimension error of the electric connector or a deviation of a mounting position but also a dimension error of a chassis or the battery of the electronic device.
Because occasionally the battery is moved in the chassis of the electronic device, unless a contact pressure of a contact spring is sufficiently increased, there is a possibility of generating temporary blackout in which the electric touch of the contact spring with the electrode of the battery is instantaneously lost. For example, the mobile telephone is powered off when the temporary blackout is generated in a mobile telephone in a standby state, and incoming processing cannot be performed unless the mobile telephone is powered on again.
In the electronic device such as the mobile telephone, there is a demand to reduce dimensions of the electric connector in order to realize the miniaturization of the device. Although the contact spring is shortened when the electric connector is simply miniaturized, a bending deformation amount of the contact spring is increased, and a partially large stress is concentrated. When the applied stress exceeds an elastic limit, the contact spring is plastically deformed to generate so-called wear in which a displacement amount or a contact pressure of the contact is lost. Because the stress concentration is relaxed when the contact spring is thinned, the plastic deformation is hardly generated. However, the elastic force is decreased due to the thinned contact spring, and a contact pressure of the contact is decreased.
For example, Japanese Unexamined Patent Publication No. 2008-218035 discloses a battery connecting electric connector in which the contact spring snakes into a substantial S-shape. However, wear is easily generated when the electric connector is miniaturized.
Japanese Unexamined Patent Publication No. 2001-237015 discloses a contact including two thin spring portions that are extended in parallel in order to fix a displacement direction of the contact, and both ends of the spring portions are connected. In the contact of Japanese Unexamined Patent Publication No. 2001-237015, the contact has a small displacement amount because only the spring portions extended in parallel are elastically deformed. When compared with the case where one thick spring is used, the contact of Japanese Unexamined Patent Publication No. 2001-237015 has no particular advantage with respect to plastic deformation caused by stress concentration.